This invention relates in general to Open Telecom Platform (OTP) communication systems, and more particularly to a remote peripheral switch connected to a main controller for performing local management in the event of loss of communication with the main controller.
Open Telecom Platform (OTP) represents a generic platform for the development of a wide range of telecommunications products encompassing both traditional PBXs and emerging convergent CTI systems. It provides generic services and capabilities, both hardware and software, for use as basic building blocks in specific product instances. Examples of software applications are voice mail and automated attendant which may be invoked using APIs (Application Programming Interfaces) such as TAPI (Telephony Application Programming Interface). Hardware examples include primary power interconnects (e.g. AC mains or DC input), PSTN interfaces (e.g. LS/Class and T1), and on-premise interfaces (e.g. Digital Network Interface Card (DNIC), fiber, etc.)
In an OTP system, a plurality of nodes may be interconnected and connected to external interfaces (e.g. the PSTN). A master node may be connected to one or both of a smart slave node or a dumb slave node. Each of the nodes includes a plurality of Node Interconnect Cards (NICs). The master node and smart slave node further include intelligence functionality in the form of a Real Time Processor (RTP). The interconnect media between nodes can consist of a single or multiple paths and, architecturally, may be realized as point-to-point connections or as paths provided via a network.
The master node exerts fundamental responsibility for real-time telephony functionality within the system. This node is able to determine its responsibility by detecting one of either a full system program load (e.g. via a program card or flash memory), or a prime program download (e.g. by means of an Ethernet port connected to a remote system). In some embodiments-the master node RTP will provide the sole processing function for the OTP system. In other embodiments, subordinate processing functions may be provided in other nodes, such as smart slave nodes, in which case the master node RTP establishes the operational parameters for the subordinate processing functions (e.g. via initialization and a subordinate download operation).
The smart slave node provides at least one subordinate processing function via its RTP, for controlling its associated node. Other processors may be resident on the node for providing other system functions, but only one RTP assumes node control responsibility.
The dumb slave node provides no node control processing functionality. Instead, its NIC acts as a proxy for a remote node controller (i.e. master node or smart slave node). It will be appreciated that the dumb slave node may incorporate processing resources, none of which provide a node control function.
In the context of OTP a PBX main controller functions as the master node to manage calls for all devices in the communication system. With geographical distribution of remote peripherals, loss of communication with the main controller is possible. In the event of a loss of communication between the main controller and a remote peripheral, it is desirable that call management be performed locally within the peripheral to ensure continued service to users connected to the peripheral.
Geographically distributed remote nodes (intelligent peripherals) are known in the prior art for managing local call control. The remote nodes are connected to a hub, which is also a main controller but which does not manage call control within the remote nodes. The remote nodes communicate with the hub via a peer-to-peer networking protocol such as DPNSS or Q.SIG. Accordingly, the remote nodes function as main controllers (i.e. master nodes) in and of themselves, with the attendant costs and system management considerations.
According to the present invention, local handling of calls is provided to individual devices within the peripheral in the event of loss of communication with the main controller. Handoff of control from the main controller to the remote peripheral is seamless since the call handling takes place as individual device requests occur. Handoff of call control from the remote peripheral to the main controller is similarly seamless upon completion of a call being serviced by the remote peripheral, without a loss of system integrity. The level of call control provided by the remote peripheral can be minimal (i.e. POTS) or rich in features provided by specific devices in the remote peripheral.